Drawing tablet.
If you want to do digital art, but don't have on, get one. They are a digital artist's best friend. Doesn't matter what one. For a beginner or maybe someone who doesn't want a pricey one, go for Wacom and their Bamboo series. The Bamboo Pen is all you need to start, nothing fancy, unless of course you want to. But you really really need one if you're wanting to do digital art. Unless you want to buy an art program, this is all you'll need to buy for it.

If you want to focus on actually drawing and painting, then Paint Tool Sai is what I recommend. This is the free trial. It's not hard to find a full download if you don't want to pay.
If you have Photoshop, then that's good too. Though it's more for graphics and editing, Paint Tool Sai is made for drawing.

Those are the dead basics. If you want to know more, reply or message me.

Photoshop is wonderful for actual painting.
Oh, and this one as well:

This user offers lots of tips and tricks on how to digitally paint humans, and create skin tones. Some of her videos are semi-nsfw though. Artistic nudity

https://www.youtube.com/channel/UCifOaTniAm4rPFEju-tsPRw